package com.hmdp.service.impl;

import cn.hutool.core.bean.BeanUtil;
import cn.hutool.core.util.BooleanUtil;
import cn.hutool.core.util.StrUtil;
import com.baomidou.mybatisplus.extension.plugins.pagination.Page;
import com.hmdp.dto.Result;
import com.hmdp.dto.ScrollResult;
import com.hmdp.dto.UserDTO;
import com.hmdp.entity.Blog;
import com.hmdp.entity.Follow;
import com.hmdp.entity.User;
import com.hmdp.mapper.BlogMapper;
import com.hmdp.service.IBlogService;
import com.baomidou.mybatisplus.extension.service.impl.ServiceImpl;
import com.hmdp.service.IFollowService;
import com.hmdp.service.IUserService;
import com.hmdp.utils.SystemConstants;
import com.hmdp.utils.UserHolder;
import org.springframework.data.redis.core.StringRedisTemplate;
import org.springframework.data.redis.core.ZSetOperations;
import org.springframework.stereotype.Service;

import javax.annotation.Resource;
import java.util.*;
import java.util.stream.Collectors;
import java.util.stream.Stream;

import static com.hmdp.utils.RedisConstants.BLOG_LIKED_KEY;

/**
 * <p>
 *  服务实现类
 * </p>
 *
 * @author 虎哥
 * @since 2021-12-22
 */
@Service
public class BlogServiceImpl extends ServiceImpl<BlogMapper, Blog> implements IBlogService {
    @Resource
    private IUserService userService;
    @Resource
    private StringRedisTemplate stringRedisTemplate;
    @Resource
    private IFollowService followService;
    @Override
    public Result queryHotBlog(Integer current) {
        Page<Blog> page = query()
                .orderByDesc("liked")
                .page(new Page<>(current, SystemConstants.MAX_PAGE_SIZE));
        // 获取分页结果
        List<Blog> records = page.getRecords();
        records.forEach(blog -> {
            queryBlogUserById(blog);
            isBlogLiked(blog);
        });
        return Result.ok(records);
    }
    @Override
    public Result queryBlogById(Long id){
        Blog blog = getById(id);
        if (blog == null) {
            return Result.fail("博客不存在");
        }
        queryBlogUserById(blog);
        isBlogLiked(blog);
        return Result.ok(blog);
    }
    @Override
    public Result likeBlog(Long id) {
        //获取当前登录对象
        Long userId= UserHolder.getUser().getId();
        //判断当前用户是否已经点赞
        String key=BLOG_LIKED_KEY+id;
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        if(score==null){
            boolean flag = update().setSql("liked=liked+1").eq("id", id).update();
            if(flag){
                stringRedisTemplate.opsForZSet().add(key,userId.toString(),System.currentTimeMillis());
            }
        }else {
            boolean flag = update().setSql("liked=liked-1").eq("id", id).update();
            if(flag){
                stringRedisTemplate.opsForZSet().remove(key,userId.toString());
            }
        }
        return Result.ok();
    }

    @Override
    public Result queryBlogLikes(Long id) {
        String key=BLOG_LIKED_KEY+id;
        Set<String> top5 = stringRedisTemplate.opsForZSet().range(key, 0, 4);
        if(top5==null||top5.isEmpty()){
            return Result.ok(Collections.emptyList());
        }
        List<Long> ids = top5.stream().map(Long::valueOf).collect(Collectors.toList());
        List<UserDTO> userDTOS =userService.listByIds(ids).stream().map(user -> BeanUtil.copyProperties(user, UserDTO.class)).collect(Collectors.toList());
        return Result.ok(userDTOS);
    }

    @Override
    public Result saveBlog(Blog blog) {
        //获取当前登录用户
        UserDTO user = UserHolder.getUser();
        blog.setUserId(user.getId());
        boolean isSuccess = save(blog);
        //查询所有粉丝
        List<Follow> follows = followService.query().eq("follow_user_id", user.getId()).list();
        for (Follow follow : follows) {
            Long userId = follow.getUserId();
            String key="feed:"+userId;
            stringRedisTemplate.opsForZSet().add(key,blog.getId().toString(),System.currentTimeMillis());
        }
        return Result.ok(blog.getId());
    }
    //滚动分页查询
    @Override
    public Result queryBlogOfFollow(Long max, Integer offset) {
        //虎丘当前用户id
        Long userId = UserHolder.getUser().getId();
        String key="feed:"+userId;
        Set<ZSetOperations.TypedTuple<String>> typedTuples = stringRedisTemplate.opsForZSet().reverseRangeByScoreWithScores(key, max, System.currentTimeMillis(), offset, 2);
        if(typedTuples==null&&typedTuples.isEmpty()){
            return Result.ok();
        }
        //解析blogId,mintime,offset
        List<Long> ids = new ArrayList<>(typedTuples.size());
        long minTime=0;
        int os=1;
        for(ZSetOperations.TypedTuple<String> typedTuple : typedTuples){
             ids.add(Long.valueOf(typedTuple.getValue()));
            long time=typedTuple.getScore().longValue();
            if(time==minTime){
                os++;
            }else {
                minTime=time;
                os=1;
            }
        }
        //根据id查询blog
        String idStr = StrUtil.join(",", ids);
        List<Blog> blogs = query().in("id", ids).last("order by field(id," + idStr + ")").list();
        for(Blog blog : blogs){
            queryBlogUserById(blog);
            isBlogLiked(blog);
        }
        ScrollResult scrollResult = new ScrollResult();
        scrollResult.setList(blogs);
        scrollResult.setOffset(os);
        scrollResult.setMinTime(minTime);
        return Result.ok(scrollResult);
    }

    private void isBlogLiked(Blog blog){
        if(UserHolder.getUser()==null){
            return;
        }
        //获取当前登录对象
        Long userId= UserHolder.getUser().getId();
        //判断当前用户是否已经点赞
        String key=BLOG_LIKED_KEY+blog.getId();
        Double score = stringRedisTemplate.opsForZSet().score(key, userId.toString());
        blog.setIsLike(Objects.nonNull(score));
    }
    public void queryBlogUserById(Blog blog) {
        // 检查 blog 是否为 null
        if (blog == null) {
            throw new IllegalArgumentException("Blog 对象不能为空");
        }

        // 获取 userId 并检查是否为 null
        Long userId = blog.getUserId();
        if (userId == null) {
            throw new IllegalArgumentException("Blog 的 userId 不能为空");
        }

        // 获取用户信息并检查是否为 null
        User user = userService.getById(userId);
        if (user == null) {
            throw new IllegalArgumentException("未找到对应的用户信息，userId: " + userId);
        }

        // 设置博客的图标和名称
        blog.setIcon(user.getIcon() != null ? user.getIcon() : "default_icon.png");
        blog.setName(user.getNickName() != null ? user.getNickName() : "未知用户");
    }

}
